AD/Arriel/34 Module M05 Lubrication Duct (Cth)

AIRWORTHINESS DIRECTIVE

For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.001(1) of CASR 1998.  The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.

Turbomeca Turbine Engines - Arriel Series

AD/ARRIEL/34 Module M05 - Lubrication Duct 8/2009 TX

Applicability:

Arriel 1A1, 1A2, 1B, 1C, 1C1, 1C2, 1D, 1D1, 1E2, 1K, 1K1, 1S and 1S1 turbo-shaft engines, all serial numbers if modified by TU332 and fitted with Modules M05 (Reduction Gear Box) as identified in figure 1 of Turboméca Mandatory Service Bulletin (MSB) A292 72 0825 Version A dated 27 May 2009.

Serial numbers of Modules M05 affected by this AD are listed in figure 1 of Turboméca MSB A292 72 0825 Version A.  The engine serial numbers are also provided for information when available.  In case of conflicts between serial numbers Turboméca should be contacted for resolution.

Note 1:  These engines are known to be installed on, but not limited to, the following helicopters:

Eurocopter AS350B/BA/BB/B1/B2, EC145/MBB-BK117-C1 and AS365N, Agusta A109K2, Sikorsky S-76A+ and S-76A++.

Requirement:

1.    a)    Inspect the M05 lubrication duct for presence of oil leakage, as instructed in paragraphs 1.C.(1)(a), 2.A and figure 2 of Turboméca MSB A292 72 0825 Version A.

If oil leakage is found - Apply the repair procedure defined in paragraph 2.B.(1) and figures 3 and 4 of Turboméca MSB A292 72 0825 Version A.

b)    If oil leakage is not found - Repeat the inspection as instructed in paragraphs 1.C.(1)(a), 2.A and figure 2 of Turboméca MSB A292 72 0825 Version A.

c)    Perform the regular oil leakage check, as defined in Chapter 05-20 of the applicable Arriel 1 Engine Maintenance Manual, paying particular attention to the M05 lubrication duct per figure 2 of Turboméca MSB A292 72 0825 Version A.

2.    Apply the repair procedure defined in Requirement 1a of this AD.

Applying the repair procedure defined in paragraph 2.B.(1) and figures 3 and 4 of Turboméca MSB A292 72 0825 Version A is terminating action for this AD.

The use of later approved revisions of these documents is acceptable for compliance with the requirements of this AD.

Note 2:  EASA emergency AD 2009-0117-E dated 2 June 2009 refers.

Compliance:

For Requirement 1a - Before next flight after the effective date of this AD, unless previously accomplished.

For Requirement 1b - During the next 75 flight hours after the effective date of this AD - every 4 flight hours or after the last flight of the day, whichever comes first.

For Requirement 1c - Following completion of 75 flight hours after the effective date of this AD - after the last flight of the day.

For Requirement 2 - Within 8 months after the effective date of this AD.

This Airworthiness Directive becomes effective on 5 June 2009.

Background:

Non compliant lubrication ducts, located in Module M05 (Reduction Gear Box) front casing, may have been installed during production and repair.

This non compliance may lead to a loss of the lubrication duct plug, followed by a quick draining of the oil tank without indication to the cockpit through low oil pressure warning.  This could lead to an uncommanded in-flight shut down.  On a single-engine helicopter, the result may be an emergency autorotation landing.

In addition, an oil leak following the loss of the lubrication duct plug could lead to an engine fire.

James Coyne
Delegate of the Civil Aviation Safety Authority

3 June 2009